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Flashcards in Epilepsy Deck (26)
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1

What does neuronal transmission occur via?

The neuronal action potential

2

What is dysfunction of the neuronal action potential the fundamental basis of?

Epilepsy and seizure disorders

3

What do action potentials occur due to?

Depolarisation of the neuronal cell membrane propagating along the axon in a wave

4

What does the wave of depolarisation of the neuronal cell membrane lead to?

The release of neurotransmitters across the axon terminal

5

In what fashion do action potentials occur?

'All or nothing'

6

What do action potentials occur as a result of?

Local changes in membrane potential caused by a net positive influx of ions

7

What does membrane potential vary with?

Activation of various ligand-gated channels

8

What affects the ligand-gated channels in the neurone?

Binding to neurotransmitters, or changes in the transmembrane potentials

9

What can a cellular hyper excitable state result from?

- Increased excitatory factors
- Decreased inhibition
- Alteration in voltage-gated ion channels
- Change in ion concentrations

All of these favour membrane depolarisation

10

Where are neurotransmitters released from?

The presynaptic terminal at the synapse

11

What happens once neurotransmitters are released from the presynaptic terminal?

They bind to specific receptors on the post-synaptic membrane for that ligand

12

What does ligand binding to the post-synaptic terminal cause?

Channel activation and movement of ions in or out of the cells

13

What are the major neurotransmitters in the brain?

- Glutamate
- Gamma-aminobutyric acid (GABA)
- Acetylcholine (ACh)
- Noradrenaline
- Dopamine
- Serotonin

14

What other molecules are thought to modify neurotransmission?

- Neuropeptides
- Hormones

15

What is the difference between neurotransmitters and molecules such as neuropeptides and hormones, in terms of neurotransmission?

Molecules such as neuropeptides and hormones are thought to modify neurotransmission over longer time periods

16

What is the major excitatory neurotransmitter?

Glutamate

17

Give 2 examples of subtypes of glutamate receptors?

- AMPA
- NMDA

18

What are glutamate receptors permeable to?

Sodium and potassium

19

What does the movement of sodium and potassium through glutamate receptors lead to?

Depolarisation and generation of the action potential

20

What can lead to channel dysfunction?

Situations leading to altered brain tissue physiology, such as infection, inflammation, or vascular compromise

21

What can situations leading to altered brain tissue physiological lead to?

Seizure activity
Often also results in various other neurological symptoms

22

What do genetic channelopathies cause?

Malfunction of a particular ion channel

23

What do genetic channelopathies often have as part of the phenotypical presentation?

Epilepsy

24

Give 2 examples of genetic channelopathies?

- SCN1A sodium channelopathy
- CACNA1A channelopathy

25

How does SCN1A sodium channelopathy present?

Often presents with a range of troublesome seizures, from frequent febrile seizures, the syndrome of generalised epilepsy with febrile seizures plus (GEFS+), as well as severe myoclonic epilepsy of infancy

26

What is CACNA1A channelopathy associated with?

Migraine disorders such as hemiplegic migraine